Thermoelectric devices are solid state semiconductor devices that, depending on the particular application, can be either Thermoelectric Coolers (TECs) or Thermoelectric Generators (TEGs). TECs are solid state semiconductor devices that utilize the Peltier effect to transfer heat from one side of the device to the other, thereby creating a cooling effect on the cold side of the device. Because the direction of heat transfer is determined by the polarity of an applied voltage, thermoelectric devices can be used generally as temperature controllers. Similarly, TEGs are solid state semiconductor devices that utilize the Seebeck effect to convert heat (i.e., a temperature difference from one side of the device to the other) directly into electrical energy. A thermoelectric device includes at least one N-type leg and at least one P-type leg. The N-type legs and the P-type legs are formed of a thermoelectric material (i.e., a semiconductor material having sufficiently strong thermoelectric properties). In order to effect thermoelectric cooling, an electrical current is applied to the thermoelectric device. The direction of current transference in the N-type legs and the P-type legs is parallel to the direction of heat transference in the thermoelectric device. As a result, cooling occurs at the top surface of the thermoelectric device, and the heat is released at the bottom surface of the thermoelectric device.
Thermoelectric systems that use thermoelectric devices are advantageous compared to non-thermoelectric systems because they lack moving mechanical parts, have long lifespans, and can have small sizes and flexible shapes. However, there remains a need for thermoelectric devices with increased performance and longer lifespans.